Originally video surveillance was based on analog technology such as closed circuit television (CCTV) and recording on video tapes. This was fine for recording an event, but such surveillance systems didn't broadcast actual live information, so such surveillance wasn't practical for monitoring locations, for instance, from a remote location to obtain real-time information. Moreover, picture quality was typically grainy and tapes needed to be changed regularly.
Other sources of video footage often have been citizens with a camera. Footage of an event may be captured by the citizen, but usually this footage is turned in to authorities or news agencies at a time after the event and is not useful as real-time information to possibly prevent a crime or terrorist act.
As technology developed, real-time video cameras replaced analog technology. For example, real-time video cameras were mounted on top of poles for traffic surveillance. These systems became accessible though broadcast stations and then the internet. This type of surveillance allowed real-time viewing of traffic events from fixed locations. Such systems have also been set up by security firms that place video cameras inside and outside buildings for surveillance. However, video data obtained from stationary sources, such as traffic cameras, often are too far from the scene or facing the wrong direction. It would be difficult and expensive to provide cameras on all roads in a given area to provide full coverage.
Cameras also have been mounted in vehicles, such as police cars, for recording events. These cameras record events such as arrests and pursuits. The recording of these events provide evidence for prosecutors, but also may provide a deterrent if the suspect knows he or she is being recorded.
Real-time video data is becoming increasingly important to provide security and legal justification for court rulings, e.g. subpoenas. Real time video data can provide information from an event such as a scene of a crime, a car accident, terrorist activity, and the like. Law enforcement, crime investigators, and terrorist specialists, for example, can use real time video data to catch criminals or prevent crimes or terrorist acts.
It is therefore desired to collect real-time video data feed from several sources via communications and then integrate the data into a composite to determine a sequence of events such as at a scene of a crime, a car accident, a terrorist event, and the like, or to compare real time video to archived video or still picture data to identify unusual or out-of-place objects.